Liverpool will be contacted to “acknowledge the error.”
The Colombia international was played behind by Mohamed Salah to fire into the corner of the net shortly after Curtis Jones’ red card to give his side the lead.
A statement read: "PGMOL acknowledge a significant human error occurred during the first half of Tottenham Hotspur v Liverpool.
"The goal by Luiz Diaz was disallowed for offside by the on-field team of match officials. This was a clear and obvious factual error and should have resulted in the goal being awarded through VAR intervention, however, the VAR failed to intervene.
"PGMOL will conduct a full review into the circumstances which led to the error.
"PGMOL will immediately be contacting Liverpool at the conclusion of the fixture to acknowledge the error."